PARIS: A study conducted by Caen University in France published that rats fed a lifelong diet of one of the bestselling strains of genetically modified corn suffered tumours and multiple organ damage.

Scientists said the results raised serious questions about the safety of GM foods and the assurances offered by biotech companies and governments.

The study – led by molecular biologist Professor Gilles-Eric Seralini, a critic of GM technology, and published yesterday in US journal Food and Chemical Toxicology – said the GM corn and Roundup weedkiller ‘may cause hormonal disturbances in the same biochemical and physiological pathway’.

The corn was genetically modified to withstand spraying with glyphosate, the main chemical in the weedkiller Roundup, developed by Monsanto.

The idea is that the corn can be sprayed without being damaged, while weeds are destroyed.

The tests looked at the impact of several scenarios including eating the GM corn (NK603), eating the GM corn sprayed with Roundup, and consuming Roundup at low doses in water.

The results were compared against those for a control group fed a ‘clean’ diet without GM or Roundup.

The researchers found that 50 to 80 per cent of female rats developed large tumours by the beginning of the 24th month, with up to three tumours per animal when only 30 per cent of the control rats developed tumours.

Up to 70 per cent of females died prematurely compared with only 20 per cent in the control group. Tumours in rats of both sexes fed the GM corn were two to three times larger than in the control group.

The large tumours appeared in females after seven months, compared to 14 months in the control group.

The team said the tumours were ‘deleterious to health due to a very large size’, making it difficult for the rats to breathe and causing digestive problems.

Significantly, the majority of tumours were detectable only after 18 months – meaning they could be discovered only in long-term feeding trials.